Rotatable directional antenna attachment for use with a vertical antenna rod



May 1 1968 c. F. STROHMEYER, JR 3,383,694

ROTATABLE DIRECTIONAL ANTENNA ATTACHMENT FOR USE WITH A VERTICAL ANTENNAROD FilSd Feb. 15, 1965 T 14 54 2/ 25 1 5- /6 n l /2Z 5 INVENTOR /9Car/l F .Sfro/zmeyer, Jr

F T- BY ATTORNEY United States Patent 3,383,694 ROTATABLE DERECTIONALANTENNA ATTACH- llzigllgll FOR USE WITH A VERTECAL ANTENNA Carl] F.Strohmeyer, in, RED. 2, St. Pauls, N.C. 28384 Filed Feb. 15, 1965, Ser.No. 432,510 3 Claims. (Cl. 343-833) ABSTRAQT OF THE DISCLOSURE Adirectional antenna attachment for use with an installed vertical activeantenna rod having an insulation mounting member at its lower endcomprising a horizontally elongated metallic base provided intermediateits ends with an aperture for rotatable positioning of said base on thestated mounting member, a director antenna and a reflector antenna rodcarried by opposite end portions of the base, and means adjustablymounting the director and reflector antenna rods on the base formovement thereof toward and away from the aperture. The base comprises aplurality of slidably connected and longitudinally extensible andretracted base portions. Both the director and reflector antenna rodsinclude a plurality of slidably telescoped extensible and retractablerod sections.

This invention relates to new and useful improvements in directionalantennas used for radio or similar purposes, and in particular theinvention concerns itself with a directional antenna embodying avertical active antenna rod together with director and reflector antennarods carried by a horizontally elongated base at opposite sides of theactive rod, the base being rotatable in a horizontal plane to permit theantenna to be oriented in a desired direction for optimum transmissionand/or reception of signals.

The principal object of the invention is to provide a directionalantenna of this type which is very simple in construction, highlyefilcient in operation, which may be quickly and easily adjusted as topositional relationship between the director and reflector rods and theactive rod, and which may be conveniently folded or collapsed into acompact form when it is not in use.

While the directional antenna of the invention has general utility, itis especially adapted for use in the environment of mobile antennas suchas are commonly carried by automobiles or other vehicles. In such anenvironment, a conventional single active antenna already provided onthe vehicle may be readily converted into a directional antenna bysimply applying the director and reflector rods of the invention withtheir carrying base to the conventional active antenna to obtain thedesired directional transmission and/or reception of signals.

Other objects and advantages of the invention will become apparent fromthe following description taken in conjunction with the accompanyingdrawings, wherein like characters of reference are used to designatelike parts, and wherein:

FIGURE 1 is a side elevational view of the directional antenna of theinvention;

FIGURE 2 is a top plan view thereof;

FIGURE 3 is an enlarged, fragmentary sectional view, taken substantiallyin the plane of the line 3-3 in FIG- URE 2; and

FIGURE 4 is a cross-sectional view, taken substantially in the plane ofthe line 4-4 in FIGURE 3.

Referring now to the accompanying drawings in detail, the directionalantenna in accordance with the invention is designated generally by thereference numeral and embodies in its construction a conventional activeantenna 11 and what may be referred to as a directional antennaattachment 12. The active antenna 11 is of the usual type including avertical rod 13 provided at its lower end with a mounting member 14 ofinsulating material, the member 14 being suitably secured to supportingstructure, as for example, to the top of a vehicle indicated by thedotted lines 15. The mounting member 14 includes the usual hexagonalbottom portion 14' and a substantially semi-spherical upper portion 14(see FIG. 3), the upper portion 14 being equipped with a metallic socket16 in which the lower end of the rod 13 is secured.

The directional antenna attachment 12 of the invention comprises ametallic, horizontally elongated base 17, including an invertedchannel-shaped center portion 18 and a pair of strap-like end portions19 which are slidably telescoped in the ends of the center portion, aswill be clearly apparent from FIGS. 3 and 4. The ends of the centerportion 18 are provided with longitudinal, openended slots 20 toadjustably receive bolts 21 carried by the inner ends of the endportions 19, so that by sliding the portions 18, 19 of the base togetheror apart, the overall length of the base may be varied. Suitable washers22 and nuts 23 are provided on the bolts 21 for locking the baseportions in a desired adjusted position.

The base center portion 18 is provided with a central opening oraperture 24 for rotatable reception of the upper portion 14" of theaforementioned mounting member 14, whereby the entire base 17 may bemanually rotated about the member 14 in a horizontal plane, it beingnoted that the base projects diametrically to opposite directions fromthe member 14, as shown.

The respective end portions 19, 19 of the base 17 carry a directorantenna rod 25 and a reflector antenna rod 26 which are identical inconstruction and each comprises a rod member 27 pivotally secured at itslower end as at 28 to a fastener 29, the latter including a socket 30similar to the aforementioned socket 16 and a bolt, nut and washerassembly 31 for fastening the socket 30 to the associated end portion 19of the base 17.

The base end portions 19 are provided with longitudinal, open-endedslots 32 which adjustably receive the bolt assemblies 31 so that thedirector antenna 25 and the reflector antenna 26 may be moved toward oraway from the active antenna 11 as desired. The slots 32 in the base endportions 19 are aligned with the slots 20 in the base center portion 18,as will be apparent from FIG. 2.

Each rod member 27 of the antennas 25, 25 preferably consists of two ormore slidably telescoped, extensible and retractable rod sections 27',27", to that the length of the antennas 25, 26 may be adjusted. Also,while these antennas are normally vertical and are held so by tighteningof the pivot means 28, the pivot means 28 may be loosened to permit theantennas 25, 26 to be moved to a folded, inoperative position on top ofthe base 17 to facilitate collapsing of the device into a compact form,when it is not in use.

In use, the antennas 11, 25, 26 are longitudinally aligned in a commonvertical plane extending diametrically of the mounting member 14, sothat by simply rotating the base 17 about the member 14, the entireantenna device may be oriented in any direction for optimum transmissionand/or reception of signals. The center portion 18 of the base 17 issimply seated on the hexagonal bottom portion 14' of the member 14 sothat it rotatably encompasses the member portion 14", with someclearance existingbetwene the base 17 and the vehicle top 15.

The active antenna rod 13 is electrically connected by a suitableconductor 33 to the transmitter and/or receiver (not shown), and aground connection is provided for the base 17 and, consequently for theantennas 25, 26. This ground connection consists of a pair of metalbrushes 34 which are preferably flexibly resilient and are suitablysecured, as at 35, to the vehicle top 15 at opposite sides of themounting member 14. The brushes 34 extend into the aperture 24 in thebase portion 17 and electrically engage the base at the edge of theaperture to effect the desired ground.

While in the foregoing there has been described and shown the preferredembodiment of the invention, various modifications and equivalents maybecome apparent to those skilled in the art to which the inventionrelates. Accordingly, it is not desired to limit the invention to thisdisclosure and various modifications and equivalents may be resorted to,falling within the spirit and scope of the invention as claimed.

What is claimed as new is:

1. An adjustable directional antenna comprising in combination, asupport surface, a mounting member of insulating material installed ontop of said support surface, a vertical active antenna rod projectingupwardly from said mounting member, a horizontally elongated baserotatably positioned on said mounting member and extending todiametrically opposite sides therefrom, a director antenna rod and areflector antenna rod carried by opposite end portions of said base, andmeans adjustably mounting said director and reflector antenna rods onthe base for movement thereof toward and away from said active antennarod said mounting member including a top portion having a circular crosssectional configuration in a transverse base plane therethrough, a pairof upright resilient metal members secured to said support surfaceadjacent to said mounting member at opposite ends of a diametric linethrough said mounting member; said base including a center portionhaving a centrally located circular aperture therein rotatably anddetachably receiving said mounting member, said aperture being ofsufficient diameter to clear said upper portion of said mounting means,but small enough so that the edge of said aperture is frictionallyengaged by said metal members, a pair of end portions carrying saiddirector and reflector antenna rods respectively, and adjustable meanssecuring said end portions to said center portion whereby the over alllength of said base may be varied.

2. The device as defined in claim 1 wherein each of said director andreflector antenna rods includes a fastener mounted on an end portion ofsaid base, and a rod member adjustably secured to said fastener andprojecting upwardly therefrom, said rod member being movable to a foldedposition overlying and substantially parallel to said base.

3. The device as defined in claim 1 wherein each of said director andreflector antenna rods includes a rod member com rising a plurality ofslidably telescoped extensible and retractable rod sections.

References Cited UNITED STATES PATENTS 2,218707 10/1940 Franz 3437l5 X2,243,523 5/1941 Davis 343--833 X 2,248,335 7/1941 Burkhart 343833 X2,473,421 6/1949 Fubini et al. 343-761 2,497,687 2/1950 Pickett et al.343-882 2,753,557 7/1956 Middlemark 343-882 X HERMAN KARL SAALBACH,Primary Examiner.

PAUL L. GENSLER, Examiner.

